must

必須、得、一定要

You must submit the application before the end of the month.

你必須在月底前把申請書送出去。

一定、想必表推測

She must be tired after driving for eight hours.

開了八個小時的車，她一定累了。

不可以、不准用於否定句

You mustn't tell anyone what you saw in there.

你不可以把在裡面看到的事告訴任何人。

一定要、務必表強烈建議

You must try the noodles at that little shop.

你一定要試試那家小店的麵。

必需品、必做之事、必看之物口語

A good raincoat is a must during the rainy season.

雨季裡一件好雨衣是必需品。